(CNN) -- On street corners, in train stations and in restaurants, the telltale signs of BlackBerry addiction are everywhere: pursed lips, a distracted look, thumbs working furiously.

People don't just use BlackBerry; once they've discovered it, they can't live without it.

Though it can be used as a phone, the BlackBerry's power lies in its ability to push e-mail automatically from the company server to the end user.

That simple concept has revolutionized corporate life. Two million BlackBerry subscribers have already signed up and their numbers are growing rapidly.

You might perhaps expect that the must-have executive gadget was unleashed on the world from somewhere inside one of the high-tech hothouses of Silicon Valley.

In fact the BlackBerry was born in the less glamorous and more laidback surroundings of Canadian technology company Research in Motion's headquarters at Waterloo, Ontario.

"I don't think people buy technology products because of the personalities of the people behind them," said RIM chairman Jim Balsillie.

But while RIM's executives have chosen to keep a low profile, they made a key decision early on to make sure their technology got maximum exposure by targeting top Wall Street executives.

"Wall Street professionals are heavily communications focused, heavily customer focused, what we found was many of those people could instantly justify the investment into this, even though it was of an unproven technology," said RIM vice president of corporate marketing Mark Guibert.

"So our approach was to go out there and really evangelize the product to people who we felt were key influencers who could make use of the product and also be seen to be using it.

"It was a viral effect. People talked so emphatically about the product and so enthusiastically they became our best marketing tool."

The early buzz around the BlackBerry got it noticed, but RIM knew that for the product to be successful they needed to convince IT professionals that BlackBerry was both easy to install and safe to use.

"We made sure the CIO was happy," said Balsillie. "The CIO has a veto and they don't hesitate to use it because they lose their jobs if the security and reliability of company data is compromised."

The BlackBerry has seen RIM's stock rocket by more than 1,000 percent since 2002, helping it become one of the most influential names in the technology sector. Yet the company has been around for 20 years, producing more modestly acclaimed wireless technology.

And Balsillie says he would rather his staff forgot about the share price and stayed focused on the research and development that have made the company successful.

Though they may have pioneered pushing e-mail onto mobile devices, the field is getting more crowded and industry analysts say RIM has its work cut out to stay ahead of the competition.

"Down the track I think you'll see some interesting shifts with respect to RIM," predicted Nicholas McQuire of technology consultants Yankee Group.

"It's going to need to make itself more flexible, in the sense it will have to be conscious of price pressure in the marketplace. Push e-mail, which is RIM's bread and butter faces quite a bit of competition."

But RIM's management believes its new wireless Web services, third party software agreements and plans to expand to new markets will keep the company on top.

"The market for BlackBerry is our core customer base and that's what we've targeted," said RIM president Mike Lazaridis.

"Recently we've expanded to the "prosumer" market -- the professionals, doctors, contractors, delivery people -- there is a whole segment of professionals out there who are self-employed."

As BlackBerry use spreads so, inevitably, will the complaints about over-worked, addicted professionals who just can't put the gadgets down. For those already suffering, Lazaridis has some advice.

"The person that means a lot to me that complains the most loudly about my BlackBerry use is my wife," he said.

"I realized a lot of executives were having the same problem so I came up with the perfect solution. I gave her one too, and I suggested they do the same."